Process of preparing sulfurized-phosphorus sulfide-olefin lubricant additive



ring properties to hydrocarbon oils. been suggested that a useful-class of lubricating oil addi- ,nlvolving olefins, as for example in U. S. Patent 2,424,402

PROCESS PREPARING SULFURIZED-PHOS- SULEIDE-OLEFIN LUBRICANT AD- Guy M. Verley, Harvey, 11]., assignor to Sinclair Refining Company, New York, N. Y., acorporation of Maine No Drawing. Application August 28, 1957 Serial No.:680,651

-;4 Claims. '(Cl; 260-139) as anti-oxidants in lubricating oils.

A sequence in the development of lubricating oil addi-' tives has been the utilization of various phosphorus and sulfur-containing compounds to impart oxidation inhibit- For example, it has tures above 340 F., as described in U. S. Patent 2,316,087, or the sulfurized phosphorus sulfide-olefin reaction product described in U, S; Patent No. 2,424,402 wherein the product is employed as a flotation agent to effect concen- In phosphorus sulfide reactions In accordance with the present invention I have dis covered an eifective method for preparing lubricating oil additives comprising the oil-soluble reacticn product of phosphorus pentasulfide, .sulfur and aliphatic olefins containing i2to 18 carbon atoms. In a particular aspect the invention is directed to the method of preparingimproved WlthlIl, a range of .temperatures where, inthe absence of sulfur, the phosphorus pentasulfide and oiefins do not react. By direct reaction of specified mole ratios of phosphorus pentasulfide, sulfur and aliphatictolefins underzcomparatively low, tempera vture conditions the sulfur combines with the P S -olefin reactionproduct to'effectgood yields of a complex material having a highsulfur content which appears to correspond to a non-polymeric cyclic tetrathiophosphoric acid of thestructure:

ycatalyst but-lalso increases the combined sulfur content of i \yields ,of a complex [mixture .by employing mole ratios of the reactants within the teml ce wherein RlfOH" rte-ort- 1 istheta'liphatic olefin radical.

In carrying--out'-:the method of-the present invention,

-rnole ratios of from about -2 to 4 1noles of olefin and about .6--to 3 moles -of'sulfur per mole of phosphorus pentasulfide are reacted at temperatures from about 250 F-t0 325 F., preferably 275 to 310F., for a-period of about one to threehours.' The reaction between the resulting in low having-poor -oil solubility,

perature range recited, the sulfur ,not only acts as a theifinal product; In the method of preparing the additocatalyze the reaction, i. e; the amount of sulfur in excess of the ratio of 'onev atom of sulfur per mole of olefin.

'lihe tsul-furized phosphorus sulfide-olefin reaction prod- -uct above describedis acidic and may be'neutralized by f percolation through petroleum adsorbents, i. ve. fullers' performance. Bhenols andalcohols such as t-oetyl phenol and 2 -ethylhexanol ,canbe reacted with the acidic reaction productin amountsuranging. from 5 to 30%, and at a temperatureof from 200 ,to 350 F. As shown herein fatter, the phosphorus sulfide-olefin reaction products treated-in this manner prior to of sludge, varnish, and carbon. 1 4 v The olefins employedin preparing the additives of this are t-riisobutylene, dodecene-l and dimerized heptene.

Th iinventioniand. its advantages will be illustrated by l atented Dec. 23, was

butylene as .can beneutralized, washed with the following examples showing specific embodiments thereof. The examples are illustrative only and are not intended as defining the breadth of the invention.

EXAMPLE I Percent Phosphorus 11.19 Sulfur 28.8 Carbon 50.74 Hydrogen 8.59

Topping of the hexane-soluble fraction at reduced pressure yielded 75 grams of triisobutylene and 369 grams of a brown resin having a parafiinic oil solubility, a phosphorus content of 9.8% and a sulfur content of 24.4%. In contrast with Example I, two moles of triisobutylene and 4 mole of P 8 were heated with vigorous stirring and the temperature maintained at the refluxing point of triisobutylene (344 F.) for 3 hours. Analysis of the mixture showed that P 8 remained insuspension and did not react with the olefin under these conditions. Hence the presence of sulfur catalyzes the reaction of olefins and P 8 to effect a rapid reaction within a range of temperatures where P 5 and olefins alone do not react.

' EXAMPLE H One mole of dodecene-l /2 mole of sulfur, and A mole of P 5 were added to 240 grams of base oil and the reactants heated with vigorous stirring. At 260 F. the mixture changed color by sulfur dissolution and at 300 F. an exothermic reaction began with a rapid increase of temperature to 330 F. The heating was stopped and in minutes the reaction had subsided whereupon a temperature of 300 F. was maintained for 3 hours until all sulfur and P 8 had dissolved. Percolation of 325 grams of the product through an 8-foot column charged with a chromatographic grade of fullers earth gave the following cuts: 7

' A. Oil, eluted by hexane, 226 g.

B. Dod'ecene monosulfide, eluted by CCI 43 g. C.sllhosphorus containing material, eluted by methanol,

Previous percolation of sulfonic and dithiophosphoric acids have shown that fullers earth neutralizes these acids with a mixture of metals (Ca, Mg, Zn, Al, etc.) having: an average combining weight of 13, thus the metal content of cut (C) is 3.5%. The sulfate ash content of cut (C) was 17.54%. I

, EXAMPLE III This preparation uses a highly sulfurized olefin instead of elemental sulfur. One mole of dodecene-l was reacted with 4 moles of sulfur at 150 C. for 12 hours. In order to remove the color bodies and unsaturates, the black reaction product was washed with commercial sulfuric: acid, water, and then dried. The product obtained constituted 85% ofthe theoretical yield of a light golden color, viscous, sulfurized olefin having a molecular weight of 780, and a NPA color of 5+. The following reactants were then charged into a S-ne'ck reaction flask equipped with a stirrer and thermowell:

4 Dodecene-l, 1 mole Sulfurized dodecene-l, 0.05 mole Phosphorous pentasulfide, 0.25 mole The reactants were heated with stirring at 210 to 220 F. for two hours and all of the phosphorus pentasulfide dissolved. The product was neutralized with 10% excess of zinc oxide in the presence of 5% water and then dried and filtered. A light colored material was obtained containing: 6.38% P; 22.8% S; 1.66% Zn; acid No., ASTM Method D-974 43; molar 8/? ratio 3.45.

EXAMPLE IV The preparation of Example III was duplicated but instead of neutralizing with zinc oxide the acidic groups were esterified by refluxing with an excess of commercial hexanol for five hours. The small amount of acidic groups remaining after esterification was neutralized with zinc oxide, the excess alcohol topped and the product filtered. A light reddish yellow material was obtained which had the following analysis: 5.35% P; 18.0% S', 0.251% Zn; acid No. ASTM Method D-974 34.6; molar ratio 8/? 3.25. I

Both products of Examples III and IV are miscible with highly refined paraflinic oils.

EXAMPLE V 156 grams of the hexane-soluble fraction of Example lwere dissolved in 500 ml. of toluene. 17 grams of zinc oxide and 10 grams of water were added with stirring and the mixture heated to the refluxing point of toluene for 1 hour. The solvent was topped, 100 grams of (150 SUS, 100 F.) paraffinic oil were added and the material was filtered to yield 320 grams of an oil-miscible product containing 4.5% phosphorus, 13.5% sulfur, and 1.76% zinc.

EXAMPLE VI 136 grams of the topped hexane-soluble fraction of Example I were dissolved in 400 ml. of toluene. 35 grams of barium oxide and 20 grams of water were added with stirring and the water was then removed by distillation of the toluene-water azeotrope. 150 grams of a 10% basic barium petroleum sulfonate in oil solution (3.6% barium, 0.82% of sulfur) were added. The toluene was distilled off and remainning material filtered to obtain 309 grams of an oil miscible product containing 16% barium, 7.8% phosphorus, and 19.8 sulfur.

EXAMPLE VII ,240 grams of dimerized heptene, 22 grams of sulfur and grams of P 5 were heated with stirring at 290 to 300 F. for 2 hours until all the solids were dissolved. The heptene dimerized was afforded by reaction of bu tylene and propylene, and the resulting dimer contained a small amount of trimer. From the crude reaction product thus obtained, a mixed salt was made in accordance with the procedure of Example V using 156 grams of crude product, 17 grams of zinc oxide and 150 grams of the barium sulfonate solution (see Example V1). grams of a light colored product were produced containing 1.4% zinc, 2.81% phosphorus, 9.17% sulfur and 1.7% barium. The barium salt made in accordance with Example VI yielded 288 .grams of a light colored material containing 4% barium, 2.47% phosphorus, and 7.76% sulfur.

Table I illustrates the effectiveness of the zinc salt of the P s -olefin-sulfur reaction product as an additive in lubricating oils useful in preventing the development of oxidation and varnish-forming materials. In general,

' depending upon the particular characteristics of the oil 5. tests were made on compositions of SAE Sufficient quantities 10W motor oil.

of additive and basic-barium petro- 6.. Composition, wt. percent:

Solvent refined 95VI Mid-Continent neutral F leum sulfonate were added to give a blended composition 200'SUS at 100 43.78 containing 0.09% phosphorus and 0.95% barium. Solvent treated Mid-Continent bright stock Table 1 Oxygen Absorbed, ml./100 Grams of Blend, 360 F.

Corn- Example Example Example Example ercial II Zn III Zn IV Zn V Zn SAE 10 Salt Salt Salt Salt 280 110 170 160 200 100 480 220 300 280 380 150 700 300 430 430 640 200 950 470 600 640 900 250 1, 250 630 840 830 1. 120 300 1, 600 770 1, 110 1, 120 1, 410 Specificati n Tests:

' lsh s11 ht slt ht Li ht; Dep )Slt in Flask Vern vainsh 1521511 first? e 1. Cu Pb Chan e, mgs +6 .50 33 5.01 Add Number 3.64 0. 30s 0 644 1. 748 1 The oxidation inhibitor is a zinc diheptyl dithlophosphate.

EXAMPLE VIII 120 SUS at 210 F 42.90

Carbonated basic barium mahogany sulfonate moles of triissobutylene, 3 moles o PhOP concentrationin mineral oil 11.60 pentasulfide and 2 moles of sulfur were heated with stlr- Zi l f Example VIII 1.67 ring in a reaction flask for about three hours at a tem- A l id 1501 Q05 perature of 284 to 320 F.; for two of these hours the Silicone polymer anti-foaming agent, 10% temperature was below 310 F. The react on be e concentration in kerosene 0.002 the P 8 and sulfur was substantially complete in three hours and the resulting mixture was heated for an additional two hours during which the temperature rose to 327 F. to increase the amount of oil-soluble reaction product. In order to reduce residual acidity and make the reaction product more oil soluble, 0.5 moles of tertiary octyl phenol were added to the reaction product at 194 F. and the mixture heated for one hour at a temperiure of 194 to 203 F. for a period of about four hours to make the product more oil-soluble and decrease its triisobutylene were topped oil at 20 mm. Hg up to a pot temperature of 266 F. 2114 grams of product were obtained which analyzed 8.6% phosphorus, 19.2% sulfur, and which had an ASTM D-974 acid no. of 77.6.

PREPARATION OF ZINC SALT 1219 grams of the above product, 100 grams of zinc oxide and 2 ml. of water were added to 500 ml. of hen- The mixture was stirred and heated to the temperature of benzene distillation. The benzene was topped at a pot temperature up to 198 F., and 1000 grams of a Mid-Continent neutral oil (160 SUS at 100 F.) were aided as a solvent. The mixture was filtered and yielded 2237 grams of an oil-miscible liquid product which analyzed 4.68% phosphorus, 10.2% sulfur and 2.57% zinc.

In order to illustrate the effectiveness of the additives prepared in accordance with the method of my invention, a lubricating composition was formulated as follows:

polymer wherein the ester group is eetyl, lauryl and octyl groups and the molecular weight is 10,000 to 15,000.

The blend analyzed:

As shown in Table II below, lubricating oil compositlons containing the additive prepared in Example VIII exhibit excellent stability and Table II L-4 ENGINE TEST RESULTS AT 280 F. CRANKCASE SUMP Varnish Rating Sludge Rating Piston Skirt 9. Rock r C vcr 10. Push Rod Owe 10. Cylinder WalL 10. crankcase 10. V

24Varnish and sludge rating, 98; average bearing loss, mg./whole bearing,

This application is a continuation-in-part of application Serial No. 528,825, filed August 16, 1955.

I claim:

1. In a process of preparing a mineral oil lubricant additive of a sulfurlzed-phosphorus sulfide-olefin reaction the step comprising the preparation 3. Theprocess ofclairn 2 wherein the metal-containing.

compound iszinc' oxide:

4; The process'of' claim-1 wherein the reaction product containing combinedkulfuris refluxed with a'lo' wer alkyl alcohol and then neutralized with a basic metalcontaining compound.

No references cited. 

1. IN A PROCESS OF PREPARING A MINERAL OIL LUBRICANT ADDITIVE OF A SULFURIZED-PHOSPHORUS SULFIDE-OLEFIN REACTION PRODUCT, THE STEP COMPRISING THE PREPARATION OF SAID REACTION PRODUCT BY REACTING IN MOLAR RATIOS OF FROM ABOUT 2 TO 4 MOLES OF C12 TO C18 ALIPHATIC MONO-OLEFIN AND ABOUT 0.6 TO 3 MOLES OF SULFUR PER MOLE OF PHOSPHORUS PENTASULFIDE AT A TEMPERATURE OF ABOUT 250* TO 375*F., SAID REACTION BEING SUBSTANTIALLY COMPLETED IN ABOUT 1 TO 3 HOURS TO OBTAIN AN OIL-SOLUBLE REACTION PRODUCT CONTAINING SUBSTANTIAL AMOUNTS OF COMBINED SULFUR. 